Call-distributing system.



G. DEAKIN & L. POLINKOWSKY.

CALL DISTRIBUTING SYSTEM.

APPLICAIION FILED MAR. 24. I917.

1,299,558; Q I Patented Apr. 8,1919.

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by MW G. DEAKIN & L. POLINKOWSKY.

CALL DISTRIBUTING SYSTEM.

APPLICATION FILED MAR. 24,1917- Patented Apr. 8,1919.

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G. DEAKIN -& L. POLINKOWSKY.

CALL DISTRIBUTING SYSTEM.

APPLICATION FILED MAR. 24. 1917.

1,299,558; Patented Apr. 8,1919.

- 3 SHEETS-SHEET 3.

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UNITED STATES PATENT @FFTGE.

GERALD DEAKIN AND LIPA. POLINKOWSKY, OF LONDON, ENGLAND, ASSIGNORS TOWESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK,'N. Y., A CORPORA-TION OF NEW YORK.

CALL-DISTRIBUTING, SYSTEM.

Specification of Letters Patent.

Patented Apr. 8, 1919.

Application filed March 24, 1917. Serial No. 157,089.

To all whom it may concern:

Be it known that we, GERALD DEAKIN, a citizen of the United States, andLIPA Po- LINKOWSKY, a subject of the Emperor of Russia, both residing atLondon, England, have invented certain new and useful Improvements inCall-Distributing Systems, of which the following is a full, clear, con'cise, and exact description. a

This invention relates to call distributing systems for telephoneexchanges, and more particularly to systems in which calls may beextended to an operators position depending upon the busy or idlecondition of such operator as electrically indicated by apparatusassociated with such'position.

The principal feature of the invention resides in the arrangement of thecircuits and apparatus in such a manner that when a call has beenextended to an operator, such operators position will be maintained busyand therefore unconnectible to all subsequent calls during apredetermined period of time, such busy condition or guard being thenremoved so that another call may be extended to her position even thoughshe has not as yet completed her duties in connection with the firstmentioned call. In practice, the time interval will be of such extentthat it is slightly less than the time in which the operator undernormal conditions attends to her duties with regard to a call extendedto her position, the time interval being such that after the busycondition or guard has been removed from the operators position theusual automatic apparatus, by which the call is extended to suchoperators position, will have sufficient time to operate to extend thecall to the position before the operator has completed'her duties withregard to the .call first extended to her position, thereby expeditingthe connection and eliminating the usual waiting time occupied by theoperation of the automatic apparatus between the instant when the opoerator is no longer busy with the previous call and the instant when thesubsequent call is actually connected to her position.

Further features of the invention will sufiiciently appear from adescription of one embodiment thereof hereinafter given.

In the drawings:

Figures 1 and 1*, when placed side by side, represent diagrammaticallyso much of a telephone exchange system as is re quired to illustrate theinvention; and

Fig. "2 illustrates schematically one arrangement, for distributingcalls to different operators, in which the busy condition or guard ismaintained upon'an operators position and removed at the desired time.

Referring to Fig. 1, 3 represents a telephone line terminating in agroup of first line-finders, oneof which is indicated at 4:, and havingassociated therewith the usual line relay 5, energized upon theinitiation of a call to "place selectable potential in the usual mannerupon the test terminal 6 of such line where it. appears in the firstline finder 4, and energizing the pilot or starting relay 7 common tothe group of lines in which such line appears. The energization of therelay-7 closes a circuit for the power magnets 8 of all of the firstline finders of the group indicated which are idle, that is, of whichthe relays 9 and 10 are deenergized. All of such idle first line findersthereupon start in motion to select and seize the call ing line in theusual manner. Immediately that thebrush 11 of one of such line findersmakes contact with the terminal 6, the relay 12 is energized, placing abusy guard upon such terminal 6'by the closure of the circuit to groundthrough the low resistance right-hand winding of such relay 12. and whenthe interrupter 13 of such line finder is opened, as the brushes of'such" line finder are centered upon the terminals of the calling line,the shunt through such interrupter around the relay 9 is removed andsuch relay energizing, the circuit of the power magnet.8 is opened, andthe circuit of the holding magnet 1 L of such line finder is closed andthe line finder brought positively to a stop with its brushes in contactwith the terminals of the calling line. The energization of the relay 9has closed a circuit in series with the circuit for the holding magnetli'for starting a pilot relay 15 common to the group of trunk linesterminating in a given set of second line finders 16.

Assuming that the operator to whose position the connecting circuit 17is individual is idle, a circuit will be established by the energizationof such relay 15 over the sequence switch contact 72-, sequence switchcontact 62 to the relays 18 of all such as are idle of said connectingcircuits.

Before proceeding farther it will be noted that all of the sequenceswitch contacts of and are operated by such sequence switchi Similarly,those sequence switch cont-acts shown within the area delimited by thedotted line in which the sequence switch 80 is'shown form a part of andare operated by such sequence switch, and those shown within the area inwhich the sequence switch 80 is shown form a part of and are operated bysuch sequence switch. These switches are of well-known construction andtheir mode of operation being known will not be described in detailherein. Upon the energization of'the relay'18 a circuit is closed overits armature and front contact, armature and back contact of the relay19, sequence switch contact 63, to the powermag'net 20 of the secondline finder 16 to which the'connecting circuit 17 is connected. Suchsecond line finder thereupon starts in motion searching for theselectable potential which has been placed upon the test terminal 21' ofthe trunk 22, extending from the first line finder 4 by the energizationof the relay 9 in theusualmanner. As soon as the'test brush 23 reachesthetermina'l 21, a circuit is completed overthe sequence switch contact65, right-hand winding of the relay 24, sequence switch contact 82 toenergize such'relay 24, which thereupon places the usual busy guard uponthe terminal 21 by the closure of the low resistance circuit through itsleft-hand winding. As soon as the brushes of the line finder 16 arecentered upon the terminals of the trunk 22 the shunt circuit around therelay 19 is opened by the interrupter 25, and such relay 19 isenergized, opening the circuit of the power magnet 20 and closing in theusual manner the circuit of the holding magnet 20 of the line finder 16to stop such line finder in the usual manner with its brushes properlycentered upon' the terminals of the trunk 22.

The energization of the relay 19 also closed circuits to energize therelay 26 and the power magnet of' the sequence switch 60. Sequenceswitch 'is driven from its first 'or normal position and under the in-"'fiuence of the local sequence switch contact 61 moves into its fourthposition. The energ ization of the relay 26, which is maintained untilthe sequence switch 60 has moved out of its second position,closes :acircuit 'over its armature and front contact and the semquence switchcontact 83 to. energize the 17 appears.

Those sequenc switch contacts and 90, are common to the position of theoperator on which the connecting circuit The power magnet of thesequence switch 80 being energized in its first or normal position, such7 sequence switch moves under the control of its local contact 81intoits fourth position. The movement of the sequence switch 80 out of. itsfirst position opens the sequence switch contact 82 and the sequenceswitch contact 83 top. On coming into its second position the circuitwas closed over the sequence. switch contact 84 and the sequence switchcontact 7 3 to drive the sequence switch'70 out of its first and, underthe control of its local contact 71, into its twelfth position. When ther sequence switch 80 comes into its fourth switch contact 85, oversequence switch con-.

tact 92 bottom, to drive the sequence switch 80 into its tenth position.V

When the sequence switch :60 is moved into its fourth position circuitswere established over the sequence switch contacts 66, i

67 and 68 for selecting and seizing an idle registering andcontrollingequipment of such operator, such selection taking. place over the switch29 diagrammatically indicated, such selection takingplace insubstantially the same manner as disclosed in Patent No. 1,167 ,646 toF. R. 'McBerty.

Since it has been assumed that this operator is idle such registeringand controlling equipment will have been found and seized before thesequence switch 80 reached its fifth position after a completerevolution of the sequence switch 90, since the switch 29.

which hunts and seizes such controlling equipment, operates atsubstantially 'the same speed as the switch 90, and the se-,

quence switch 60 has, therefore, been driven out of its fifth positionin the-known manner opening the sequenceswitch contact 66 included inthe circuit .of the "switch 29. On' coming into its tenth position,these quence switch 80 closes thesequenceswit'ch contact-85 which-againstarts the sequence 7 switch 90 to'make a complete revolution. Assequence. switch 90 is again passing its eighteenth position, a circuitis closed over sequence switch contacts 85' and 92 bottom to drive thesequence switch "80' into its eleventh position. The sequence switch 90,

therefore, when itreaches its first or normal position,jfinds thecircuit connection closed over the'sequence switch contacts 85 and 92 1top and starts on a third complete revolution. Near the completion ofthe third. revolution of the sequence switch 90 the closure of thesequence switch contact 92 bottom again causes the energization of thepower magnet of the sequence switch 80 which drives this sequence switchout of its eleventh position and passing through its twelfth,thirteenth, etc., positions, such sequence switch returns to its firstor normal position.

It will be observed that immediately upon the seizure of the trunk 22whereby a call is extended to the operators position, the apparatus ofwhich is shown, and the consequent energization of-the relays 19 and 26,the sequence switch 80 started in motion and immediately drove thesequence switch 7 0 out of its first or normal position. This caused theopening of the sequence switch contacts 72, 72 and 72 which will bemaintained open until the sequence switch returns to its first or normalposition. These sequence switch contacts as has been before noted areincluded in the common starting circuits of several groups of theconnecting circuits located upon the position of the operator inquestion. So long, therefore, as such sequence switch contacts remainopen, no calls may be extended to such operators position and none ofthe second line finders individual to the connecting circuits appearingupon such operators position may be set in motion. When, however, theJime interval necessary for the operation of the sequence switch 80 intoits thirteenth position, which time interval includes definitely thetime required for the sequence switch 90 to make three completerevolutions, has elapsed, the sequence switch 70 will be driven out ofits twelfth position by the closure of the sequence switch contact 84:bottom and such sequence switch 70 will leave its twelfth position andthen, without stopping, move into its first or normal position in whichthe sequence switch contacts 72, 72' and 72* are closed. At this time,further incoming calls which have been extended to trunks such as 22accessible to the set of second line finders connected to connectingcircuits such as 17 which appear upon this operators position, willcause the operation of such second line finders 16 in the mannerhereinbefore described to extend such incoming call to a connectingcircuit upon such opera-tors position. It will, therefore, be seen thatwhen one call has been extended to the operators position such operatorsposition is maintained busy to all further incoming calls until afterthe passage of a definite interval of time as predetermined by theadjustment, arrangement and construction 10f the sequence switches 70,80 and 90. After such interval of time has passed the busy guard isremoved from such operators position and a second call may be extendedthereto. When the second call has been extended to a connecting circuitof such operators position, as has been described, and in consequencethereof energized the relays 19 and 26 individual to the connectingcircuit and second line finder to which such call has been extended, thetiming apparatus is again started in motion, opening the sequenceswitchcontacts 72, 72 and 72* and placing a busy guard upon the positionand maintaining such busy guard for the predetermined interval of time,after which they are again closed and a still further call may beextended to such operators position.

In rsum it will be seen. that under normal conditions upon the receiptof a call the operators position will be maintained busy for a periodsay of four. seconds, after which time another call may be extended toher position. If, however, a call has been extended to her positionwhich has not as yet been connected to her equipment, the test guardwill be maintained upon the position an increased interval which mayeven be as much as seven seconds, and if two calls have been connectedtosuch operators position, neither of which have as yet been extended toher equipment, the interval may be'further extended to so much, forexample, as eleven seconds.

It will, of course, be understood that the time intervals referred toare given for example only and that by the rearrangement of the circuitsin an obvious manner the period oftime elapsing in the normaloperationof the timing apparatus or in either of the abnormal oasesmentioned may be so modified as the traifc conditions of the particularexchange in which the apparatus is used may require. Generally, it willprobably be found that if the time occupied by the timing apparatus inits normal operation is about seventy-five percent; of the time normallyrequired by anoperator tocomplete her duties with regard to the averagecall, a considerable saving will be accomplished with a minimum delay toincoming calls.

Referring more particularly to Fig. 2, to the left are indicated aplurality of groups of first line finder switches such as the group i,4:. The trunks connected to these line finder switches are multipled tostationary contacts in the second line finder switches such as thoseindicated at 16, 16, the trunks from a plurality of groups of first linefinder switches appearing on each of such sets or groups of second linefinder switches. As shown, the first three groups of line finderswitches from the top of the figu're'terminate inthe second line finderswitches 16, 16, 16. The next three groups of line finder switchesterminate'in the second line finder switches 50, 50, 50, and a third setof groups of line finder switches terminate in the second linefinder-switches 51, 51, 51. Associated with and controlled by the trunksterminating in the second line. finder switches 16 is the commonstarting or pilot relay 15. As has been described in connection with'Fig; 1, this relay is energized Whenever a 'call has been extended to atrunk of-the first V group and closes a circuit over-the sequence switchcontact 72 of the sequence switch 7 0. to start in motion all of thesecond line finder switches 16. connected to connecting circuits in theseveral operators posltions of. which three. are indicated. If thesequence switch 70 on any of these operators is out of its normalposition, lndicating that the operator is busy, the sequence switchcontact 72, individual to such operators position, will be opened andnone of the second line finders l6connected to connecting circuits ofsuch operatorsposition will be started in motion. correspondingly, ifthe call had been extended by a first line finder to a trunk of thesecond group the pilot or starting relay 15, common to such group, wouldhave been energized and the starting circuit closed to the second linefinders 50 connected to connectingcircuits appearing upon operatorspositions of such operators as are idle, over the sequence switchcontact 72. Similarly, if the call is extended by a first line finderswitch to a trunk of the third group, the relay l5 will be energized andthe starting circuit es 'tablished will include the sequence switchcontact 72 on various operators positions ofsuch operators as are idle.On this figure of the drawings the common, control of the several relays15, 15 and 15 is indicated by a loop associated with the respectivegroups of trunks. Only the relays 18 and the sequence switch contact 62associated with the several connecting circuits indicated are shown onthis figure, as by ref erence to Fig. 1 the complete operation withregard to any particular connecting'circuit may be readily understood.

Referring to Fig. 2 therefore,and'assuming all three operators are idle,a call extended to the trunk 22 by one of the first line finders 4 willstart in motion the second line finders 16 upon all of such operatorspositions. 'When one of these second line finders16 has selected andseized the trunk 22, the remaining secondline finders 16 will be stoppedin the usual manner, which need not be herein described, and thesequence switchcontacts 72, 72 and72 of the same operators position asthesecond line finder 16 which has selected and seized the trunk will beopened for a predetermined interval f of time, as hereinbeforedescribed. 'Meanwhile, to calls extended by any other or the first linefindersto any of the trunksshown, except the trunk in use, {will stillbeac cessible 'to the corresponding second line finders appearing on theremaining oper ators positions, If a'call has been extended to all ofthe operators positions shown and such operators are stillrbusy inconnection with-such calls, the first of such operators;

whose timing apparatus has run through its r cyclewill have the'sequenceswitch contacts 72, .72 and/72 of her position again closed and theappropriate idle second line finders of such operators position will bestarted in motion for a subsequent call in the 'manner hereinbeforedescribed. j g V l/Vhile each operators position contains connectingcircuits to which are connected second line finders of the differentsets or groups having access to the different groups,

of trunks leading from the first line find-j ers, only such second linefinders as have access to the groups of trunks to which a call has been.extended will start in operation,

' but immediately one of such second line finders has seized thetrunk towhich the call has been extended, the entire position 7 of such operatorwill be rendered busy until the timing apparatus individual to suchoperators position has run through its cycle, when another callmay beextended to such operators position from any of the groups of trunks towhich the second line finders] of such operators position have accessover such second-line finders as may be idle of. the appropriate set orgroup individual to such operators position.

In systems utilizing line findersdof the type having no normal position,such as those diagran'nnatically illustrated in Fig.1,

the position to which the sequence switch'86 is individual. i

What is claimed is:

1. The combination with an operato sitlon of meansforselecting thesameand extending a call thereto and apparatus actue. ated when a call hasbeen extended. to a trunk at said position to prevent the extension ofanother call to the position for adefinite time interval substantiallycommensu-V rate withthetime employed by an operator. establishing anaverage connection.

2. The combination with an operators p9 sition of trunks extendingthereto, means ,7

for extending call to one of said trunks,

and apparatus responsive to the extension of a call to a trunk forrendering subsequent calls unconnectib-le thereto for a definite timeinterval after the first call has been extended to the position.

3. The combination with an operators position of means for selecting thesame an subsequently extending a call to a trunk at said position, andapparatus rendered active when a call has been extended to said trunk toprevent for a definite time interval the selection of such position bysubsequent calls.

t. In a call distributing system, means for selecting an operatorsposition and extending a call to a trunk at said position, means at sucha position for establishing connections between calling and calledlines, and

, means independent oi such connecting means for rendering the positionbusy to subsequent calls for a predetermined interval after thedistribution of a call to said trunk.

5. In a call distributing system, means for distributing calls to trunksat an operators position in combination with timing means at saidposition responsive to the selection of a trunk for automaticallydetermining the rate at which such calls may be distributed to suchposition independent of the condition of the connecting apparatus atsuch position.

6. In a call distributing system, automatic switches for distributingcalls to an operators position, automatic switches at such position forassociating calls distributed thereto with connecting circuits,controlling devices at said position, automatic switches for associatingcontrolling devices with con necting circuits with which calls have beenassociated, and an automatic timing switch started in operation when aconnecting circuit at the position has been taken for use for thepurpose of preventing the association of another call with a connectingcircuit at such a position until such timing switch has completed itscycle of operations.

7. In a call distributing system, means for distributing calls toconnecting circuits at an operators position, controlling apparatusadapted to be associated with such connecting circuits, a timing deviceat such position responsive to the extension of a call to a connectingcircuit adapted to introduce a time interval between the distribution ofsuccessive calls to the connecting circuits at such position.

8. In a call distributing system, calling lines, means for selecting anoperators position and extending such calling lines thereto, a positionsequence switch actuated when a calling line has been extended to theposition to render such position non-selectable to subsequent calls, anda timing device to again actuate said position sequence switch after apredetermined time interval to again render such position selectable.

9. In a call distributing system, calling lines, means for selecting anoperators position and extending such calling lines thereto, a positionsequence switch adapted to be driven from normal position when a callingline has been extended to the position to render such positionnonselectable, a timing sequence switch adapted to be driven through acycle of operations in response to the operation of such positionsequence switch, and means controlled by such timing sequence switch atthe termination of its cycle of operations to drive such positionsequence switch back to normal and render such position againselectable.

In witness whereof, we hereunto subscribe our names this 2nd day ofMarch A. D., 1917.

GERALD DEAKIN.

LIPA POLINKOWSKY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of .Patents, Washington, D. G.

